Ratchet screwdrivers are already known in the art of applying a ratchet tool for rotating a threaded fastener such as a screw. Those prior tools can be applied in both the tightening and removing processes of the threaded fastener, including use in the medical arts.
The present invention improves upon the prior screwdrivers in that it provides a ratchet screwdriver that has pivotal pawls and that provides for optimum control and operating confinement of the pawl or pawls, and the drive direction selector, and the driven gear. That produces greater precision in operation.
The pivotal pawl or pawls are snugly mounted and cooperate with the adjacent parts of the screwdriver to be accurate and secure in both the operative and inoperative positions. The selector, which operates the pawl or pawls, cooperates to lend support in both the pawl operative and inoperative positions, and it is releasably lockable in all its two or three selectable positions of operations, and it thereby secures the pawls in their selected operative and inoperative positions.
In achieving the foregoing, the screwdriver is structured and made in a manner that provides for the aforementioned features. It is constructed such that it can be assembled from its back end, rather then from the front end as with the prior art structures. The assembly imposes an axial force on the mechanism for snug containment of the ratchet. Also, it is secured by an axially movable rotation locking member and by fasteners. In that arrangement, the fasteners apply axial force on the assembly and on the drive gear for stabilizing the gear and avoiding the play of the prior art assemblies.